Type of Surgery
Information
Last updated: 02/17/2009
PRK was first performed in the 1980s and widely used in Europe and Canada in the early 1990s, but was not approved in the United States until 1995. PRK was the most popular refractive procedure until the creation of LASIK, which has a much shorter recovery time. PRK is still the preferred option for patients with thin corneas, corneal dystrophies, corneal scars, or recurrent corneal erosion.
PRK takes about 10 minutes to perform. Immediately before the procedure, the ophthalmologist may request corneal topography (a corneal map) to compare with previous maps to ensure the treatment plan is still correct. Ophthalmic personnel will perform a refraction to make sure the refractive correction the surgeon will program into the excimer laser is correct.
Patients may be given a sedative such as Valium to relax them before the surgery. Anesthetic drops will be applied to numb the eye and prevent pain during the procedure.
After the eye drops are inserted, the surgeon prepares the treated eye for surgery. If both eyes are being treated on the same day, the non-treated eye is patched. The surgeon inserts a speculum in the first eye to be treated to hold the eyelids apart and prevent movement. The patient stares at the blinking light of a laser microscope and must fixate his or her gaze on that light. The patient must remain still.
The surgeon double-checks the laser settings to make sure they are programmed correctly for the refractive error. With everything in place, the eye surgeon removes the surface corneal cells (epithelium) with a sponge, mechanical blade, or the excimer laser. With the epithelium completely removed, the surgeon will begin reshaping, or ablating, the cornea. This takes 15–45 seconds, and varies for refractive error; the stronger the error, the longer the ablation. Patients may worry that moving could cause irreversible eye damage, but they should know that, at the slightest movement, the doctor immediately stops the laser. When the ablation is completed, the surgeon places a bandage contact lens on the treated eye to protect it and allow the healing process to take place; it also eases some of the pain of the exposed cornea. The surgeon will also dispense anti-inflammatory and antibiotic eye drops to stop infection and reduce pain.
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Other Information
Photorefractive keratectomy (PRK) and Laser-Assisted Sub-Epithelial Keratectomy (or Laser Epithelial Keratomileusis) (LASEK) are laser eye surgery procedures intended to correct a person's vision, reducing dependency on glasses or contact lenses. The first LASEK procedure was performed at Massachusetts Eye and Ear Infirmary in 1996 by ophthalmologist, refractive surgeon, Dimitri Azar. The procedure was later popularized by Camellin, who coined the term LASEK for laser epithelial keratomileusis. LASEK and PRK permanently change the shape of the anterior central cornea using an excimer laser to ablate (remove by vapourization) a small amount of tissue from the corneal stroma at the front of the eye, just under the corneal epithelium. The outer layer of the cornea is removed prior to the ablation. A computer system tracks the patient's eye position 60 to 4,000 times per second, depending on the brand of laser used, redirecting laser pulses for precise placement. Most modern lasers will automatically center on the patient's visual axis and will pause if the eye moves out of range and then resume ablating at that point after the patient's eye is re-centered.
From http://en.wikipedia.org/wiki/Photorefractive_keratectomy
Other Information
Surgeons aim for results of 20/20 or better so that you can perform most daily activities without your glasses. However, there is a possibility that after surgery, you may need to wear reading glasses or corrective lenses for at least some activities.
-Eye Surgery Education Council
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